Kelsen, Hans (1881–1973)

Hans Kelsen was one of the foremost (positivist) legal theorists of the twentieth century. He taught in Vienna, Cologne, Geneva and Paris, and finished his life in America, teaching in Chicago, Harvard and Berkeley. He wrote widely, on legal philosophy, constitutional and international law, and political philosophy. Kelsen is best known for his Pure Theory of Law (Reine Rechtslehre) (1934). This is the basis of a theory which, with many changes, he espoused till he died.